Pancreatic cancer remains the fourth leading cause of death in the United States, not because of increased incidence but because it remains incredibly lethal and resistant to chemotherapy. Early diagnosis is often difficult, and only 20% of pancreatic cancer patients are candidates for surgery. The discovery of a biomarker that clearly classifies suspicious pancreatic lesions or serves as a reporter for response to chemotherapy would permit early diagnosis of and tracking of therapies for pancreatic cancer. Now, several investigators from Dartmouth may have done just that in a recently published paper in Clinical Cancer Research.

MicroRNAs (miRNAs) are small 18- to 25-nucleotide noncoding regulatory RNAs that selectively regulate gene expression by targeting the 3′-untranslated region of specific mRNAs and blocking their translation. Several miRNAs have been implicated in tumor biology, including miR-10b, which is highly expressed in metastatic cancer cell lines. In the recent report, Preis et al. evaluated the expression of miR-10b by in situ hybridization using endoscopic ultrasonography (EUS)–guided fine-needle aspirate (EUS-FNA) samples obtained from suspicious pancreatic lesions in 155 patients. The authors noted that miR-10b expression was increased in cancerous lesions, relative to benign lesions, and also showed that lower levels of miR-10b were associated with improved response to neoadjuvant chemoradiation administered before resection.

These findings suggest that miR-10b may provide the key to improving early diagnosis of this lethal disease and to predicting treatment outcome. Better than jewelry, this microRNA lends support to the notion that “good things come in small packages.”